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This thesis aimed to provide improved understanding of the spatial and temporal variability of stream temperature, the influence of riparian woodlands on thermal regimes and examples of the ecological consequences of different thermal regimes.  First, the spatial and temporal variability of temperature within a large montane river basin at nested spatial scales was established.  It was from this analysis that (i) variation that can occur at all spatial scales was observed, (ii) different physical factors are controlling these variations at all scales, and (iii) greatest differences occur between different tributaries.  The extent of riparian forestry proved to be in important factor in determining river temperatures.  The results suggest that broadleaved tree species within the riparian zone are more able to reduced incoming solar radiation and consequently control stream temperature.  This highlights the potential of riparian plantings in mitigation efforts against high temperatures under future climate scenarios.  To complement these empirical assessments, the ecological significance of observed thermal variability was assessed in a laboratory study of the growth of juvenile Atlantic salmon.  The effects of the temperature regime on growth were in the range of about 3% reduction in final length in the variable regime compared to the constant one.  Relations between invertebrate growth, adult emergence patterns and thermal regime differences related to riparian cover were assessed in relation to the mayfly <i>Baetis rhodani.  </i>Statistically significant differences in mean size and size distribution of Baetis were found in the Girnock, between all sites separated by no more than 5 km.

Thesis (Ph. D.)--University of Wyoming, 2006. / Title from PDF title page (viewed on Dec. 15, 2007). Includes bibliographical references.

Although there has been extensive research on the geomorphic and ecologic role of large woody debris (LWD) in streams, the dynamics of LWD in streams are poorly known due to various measurement difficulties during floods. In this thesis I present the results of two flume experiments on the dynamics of wood in streams. The first experiment examined the effects of piece interaction on wood transport, while the second evaluated a theoretical model predicting the threshold of movement, and factors controlling the deposition of individual logs. Flume experiments allow us to model the wood movement under a variety of piece geometries, piece concentrations, and hydraulic conditions. The first experiment showed that logs moved in three distinct transport regimes; congested, semi-congested, and uncongested transport. During congested transport the logs move as a single mass and occupy > 33 % of the channel area. Uncongested transport occurs when the logs are moving as individuals and occupy < 10 % of the channel area. Semi-congested transport is intermediate between these two transport regimes and occurs when wood moves in clumps of 2-3 logs. Transport regime was dependent upon the ration of the volumetric input rate of pieces to the flow, and to a lesser degree, the ratios of the piece length to channel width and piece diameter to channel depth. The transport regime was reflected in the deposit. Congested transport deposits have a higher portion of their pieces oriented parallel to flow than uncongested and semi-congested transport. We expect that congested transport will occur in low-order channels where input rates are high and channel geometry is small relative to piece size. Uncongested transport will dominate large channels where input rates are lower relative to flow and channel geometry is large relative to piece size. Our theoretical model and these experiments indicate that the entrainment of individual logs was dependent upon the angle of the piece, and the presence/absence of rootwads. Although previously noted as a first-order control on piece movement, piece length had little effect on the entrainment threshold, but did affect the distance transported. The distance transported decreased with increases in the ratios of the piece length to average channel width (L[subscript log]/w[subscript av]), the piece length to the radius of curvature (L[subscript log]/R[subscript c]), and the piece diameter relative to average depth (D[subscript log]/D[subscript av]). These three ratios comprise the debris roughness. Increased debris roughness caused a general decrease in distance transported. Pieces with high debris roughness can travel further than predicted if they have high momentum, and over 50 % of their channel area deeper than the depth at which the piece floats. These results indicate that flume experiments and theoretical models, tools that have been extensively used to study sediment dynamics, are a useful in examining wood dynamics. / Graduation date: 1998

Thesis (Ph.D.)--Kent State University, 2009. / Title from PDF t.p. (viewed Nov. 16, 2009). Advisor: Mark Kershner. Keywords: crayfish; stream; predation; current velocity; water depth; grain size; resource competition. Includes bibliographical references.

Thesis (M. Phil.)--University of Hong Kong, 2010. / Includes bibliographical references (leaves 169-192). Also available in print.

Thesis (Ph. D.)--University of Wyoming, 2006. / Title from PDF title page (viewed on April 16, 2008). Includes bibliographical references.

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 117-134). Also available via the Internet.

Thesis (M.S.)--Oregon State University, 1990. / Typescript (photocopy). Includes bibliographical references (leaves 97-102). Also available on the World Wide Web.

Thesis (Ph.D.) -- Griffith University, 2005. / Facsimile of the author's original dissertation. Pagination of document: xi, 238 leaves. Includes bibliographical references.